The operating voltage of the 123 is from 4 to 18 volts, personally I've never managed to cook one yet.




I've fitted 123 to 6 volt cars and used a 12 volt modern car to jump start the thing and the 123 has lived. Not that I recommend that practice, but need must...

In essence because getting rid of the points allows control over the dwell angle. It is the dwell on 2CV points ignition that fries the coil.

Ergo proper dwell angle control, vastly increased coil life.

As a new owner of an a-series I've only fitted 123 as a matter of habit due to having fitted electronic ignition on other classics I've owned, my other cars had lumenition setups, and to be honest I didn't know there was a difference!

I fitted 123 as I don't have a garage, and I bought the car leading to up to winter, and with the fact that there's a bit more work involved in getting to them means it was a no-brainer for me. However I don't like the idea of trusting a PCB stuck to the front of the car, and always carry the points in my tool bag. When I eventually get a garage I may go back to points as I can adjust them in comfort, as it was designed to run on points I think its good to have things as originally intended, getting the points set up well also helps you learn more about the car too.

The BMC A-Series engine was originally fitted with points, but Austin-Rover replaced that with electronic ignition in the mid 80s.

I'll throw my penny worth in, and just say I have 123 on my car, I bought it after a Raid Tan Hill c2002 when the condenser kept packing up and it took me 8hrs to get home. I've now done well in excess of 100,000 miles through all sorts of weather and a knackered battery or three and a journey to one of the French National meetings where the brushes in the alternator went, so I had no charging and completely flattened the battery, and it's still going. I will say though, I've never had the "performance/starting/economy benefits" that was claimed by so many who had fitted 123 prior to me. I just enjoys the increased reliability of the car.

There are in essence 4 ways of controlling the ignition on an A series engine. Each have their own strengths and weaknesses.

1) Points and condenser as was originally fitted. Advance and retard is controlled by a spring and bob weights, dwell angle is dependent on the points gap.

2) Points assisted, Boyer Bransden et al. Retain the points, condenser and bob weights. Principal advantage is that arcing across the points is eliminated, greatly extending point life.

3) Lumenition, Multic etc. Points and condenser removed, mechanical advance retained. No points to wear out, no condenser, the advance curve is still mechanical. No alteration of the ignition curve is possible but dwell angle can be controlled.

Advantage is that the electronics can be sited anywhere. Disadvantage is the lack of electronic advance control.

4) Hall effect; fitted in place of the points box. 123, DG etc. Points box and advance retard springs entirely removed. The ignition is triggered by 2 magnets placed over the pins for the bob weight springs. The electronics are in a box directly on the nose of the crank.

Advance curve(s) programmed into the ignition unit therefore the most control over advance and dwell parameters. Arguably vulnerable to weather ingress.

None of these fundamentally alter the nose of the crankshaft. If you carry a spare ready set up points box any of them can be swapped out by the side of the road. Personally even on a standard points car I never carry loose points and condenser. Always a ready adjusted and assembled points box.

There are some other variations out there BTW, including a weird French device with a magnet clipped on a fan blade and a pickup on the fan grille mesh. IMHO you don't want to go there.

thanks 250

im gonna get 123, but i'll be keeping a box in the boot along with the rest of bits n bobs i'd need, should i ever need them! at the end of the day, theres originality votes, theres the "im using it and yes you should try it" votes, and then ive got the i've never had to/needed to votes, i've heard about them packing up, but that doesnt worry me, and if my car was to have as much of a sucessfull run as yours Jonothan... then i'd be quite happy if it still works however many years later!

I fitted a DGnition last year, and it's been brilliant. I'm not anti-points, and have kept all my bits just in case, but I'm loving the hassle free motoring that the DG has given me.

I have my two cars running on 123/ignitions.
The Pick Up has a 123/UNI ignition wich has different settings for different engine types. That's not the reason I have itm but the company I bought it from only had this model in stock, and offered it to me for the price of a normal/black 123 ignition.
Runs 80000km's so far without any problems. Put it in the car, set the timing and ready.

For the Ami I first bought an electronic ignition from Club Cassis (88,50euro's), but with that the Ami didn't run right. My girlfriends 2cv and cars from friends also use this one, without problems.
So contacted a friend who doesn't use his real 123 ignition anymore, so now thats in the Ami. Put it in, set the timing and the car runs very well

Main reason for me is I never learned to set/adjust the points, and don't want to learn. Tim2cv has a good quote about this that suits me too:

I've been running 123 for a good number of years, with no problems at all. But like Jonathan, I'm completely unable to feel any improvement in performance. I carry all the bit i removed just in case!

2cv's on Luminition, was like that when I bought it. Never failed me - even when I dumped the car in a puddle where the water came in under the doors.

Mehari's as it left the factory. Both cars start first time, everytime so I've never had cause to doubt either system.